AO40TLMVIEW - decoder and viewer for AO-40 telemetry

AO40tlmview decodes the binary
telemetry
transmitted by the
AMSAT-OSCAR 40
satellite.
It provides an ncurses-based (i.e., text-mode) interface for
browsing through the telemetry blocks.
The telemetry blocks can either be read from a file
(e.g., downloaded from the telemetry archive),
or received live through a TCP or UDP connection to
a demodulator (see
below).
Furthermore, it can produce simple graphs of the telemetry,
either through
gnuplot
if running in a graphical (X11) environment,
or as a crude ASCII graph when running in a text
environment.

Many aspects of the functionality of AO40tlmview have been
inspired by Stacey Mill W4SM's telemetry program P3T for
MS-Windows, as is probably clear from the screenshot:

The current version is 1.04, released 2003-07-20.
It can be downloaded (source code and documentation)
here.
The major changes since version 1.02 (2001-10-26) are the following:

upon startup, settings are read from files .ao40tlmviewrc in the current and the home directory.

name of log file can automatically contain '@callsign', as needed for
submission to the telemetry archive; the callsign is specified in .ao40tlmviewrc .

the log file is now closed and a new file opened when passing midnight UTC.

graph of Whole Orbit Data.

If you want to decode telemetry that you receive directly
from the satellite, you will also need something to
demodulate the 400 bps audio signal into a stream of bits
that ao40tlmview can display.
There are three soundcard-based AO-40 demodulator programs
available for Linux:

Tom Sailer HB9JNX's multi-platform demodulator
p3dtelem.
I have made a patch for this demodulator to add
support for streaming telemetry over TCP;
it's available
here.
(Note: the TCP-portnumber is hard-coded as 2223 in this patch;
you may want to change it before (re)compiling.)

Phil Karn KA9Q's demodulator, which also handles the FEC blocks:
data blocks with redundant information to help the demodulator decode
blocks correctly even at very low signal-to-noise ratios or in the
presence of (spin) fading.
This demodulator and documentation about the FEC scheme are available
here.